This program is aimed at establishing a measure of the improvement that can be achieved in diagnostic radiology, by making use of a photoelectronicdigital system which does not degrade the performance intrinsicc to the x-ray sensor. Clinical research utilizing the new system will be focused upon three difficult diagnostic procedures: 1. early detection of breast cancer. 2. dental radiography for early detection of caries and periodontal disease, and monitoring the efficacy of therapy. 3. imaging of the appendicular skeleton for early identification of arthropathies, stress fractures, low contarast osseous lesions, and videodensitometry for bone loss associated with osteoporosis. Appropriate statistical studies of the results will be evaluated and compared to the performance established from conventional filmscreen radiology. The best of the fluoroscopic systems used in subtraction angiograph suffer from severe image degradation compared to the image from the sensor. This results from loss of spatial resolution in the x-ray image intensifier, coupling optics and video tube as well as loss of dynamic range through veiling glare, electronic noise and the video tube. The digital system compounds the loss of spatial resolution by pixel digitization at numbers far too low for diagnostic radiology. A system can and will be assembled able to maintain the performance of the x-ray sensor. It is based on the recent availability of manufactured components with appropriate specifications.